Adjustable manhole cover

ABSTRACT

A manhole cover assembly has an inner cylinder and an outer cylinder. An upper ratchet mechanism extends axially and circumferentially about an outwardly facing surface of the inner cylinder. A lower ratchet mechanism extends axially and circumferentially about an inwardly facing surface of the outer. The lower ratchet mechanism is configured to mesh with the upper ratchet mechanism at one of a plurality of distinct ratcheting positions. A cover plate is disposed on one of the inner cylinder and the outer cylinder. The cover plate is at a first elevation when the lower ratchet mechanism meshes with the upper ratchet mechanism at a first distinct ratcheting position. The cover plate is at a second elevation when the lower ratchet mechanism meshes with the upper ratchet mechanism at a second distinct ratcheting position. The first elevation is different from the second elevation.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No. 14/575,312, which was filed on Dec. 18, 2014.

BACKGROUND

This disclosure relates to a manhole cover, and more particularly an adjustable manhole cover. Over time, manhole cover systems can undesirably sink relative to the surrounding environment.

SUMMARY

A manhole cover assembly has an inner cylinder and an outer cylinder. An upper ratchet mechanism extends axially and circumferentially about an outwardly facing surface of the inner cylinder. A lower ratchet mechanism extends axially and circumferentially about an inwardly facing surface of the outer cylinder. The lower ratchet mechanism is configured to mesh with the upper ratchet mechanism at one of a plurality of distinct ratcheting positions. A cover plate is disposed on one of the inner cylinder or the outer cylinder. The cover plate is at a first elevation when the lower ratchet mechanism meshes with the upper ratchet mechanism at a first distinct ratcheting position. The cover plate is at a second elevation when the lower ratchet mechanism meshes with the upper ratchet mechanism at a second distinct ratcheting position. The first elevation is different from the second elevation.

In another example of the foregoing assembly, the inner cylinder and the outer cylinder are disposed about an axis, and the inner cylinder is radially inward of the outer cylinder.

In another example of any of the foregoing assemblies, the cover plate is disposed on the inner cylinder.

In another example of any of the foregoing assemblies, the inner cylinder is integral with the cover plate.

In another example of any of the foregoing assemblies, the cover plate includes openings to receive tools. The openings permit the tools to engage the cover plate.

In another example of any of the foregoing assemblies, the openings are linear slots.

In another example of any of the foregoing assemblies, the cover plate is integral with the inner cylinder.

In another example of any of the foregoing assemblies, the outer cylinder is configured to receive the inner cylinder through a top opening of the outer cylinder.

In another example of any of the foregoing assemblies, the upper ratchet mechanism is a linear gear.

In another example of any of the foregoing assemblies, the upper ratchet mechanism is a first upper ratchet mechanism. The inner cylinder further comprises a second upper ratchet mechanism extending axially and circumferentially about the outwardly facing surface. The first upper ratchet mechanism is circumferentially spaced from the second upper ratchet mechanism.

In another example of any of the foregoing assemblies, the inner cylinder comprises a third upper ratchet mechanism extending axially and circumferentially about the outwardly facing surface. The third upper ratchet mechanism is spaced circumferentially from the first and second upper ratchet mechanisms.

In another example of any of the foregoing assemblies, the lower ratchet mechanism is a first lower ratchet mechanism. The outer cylinder further comprises a second lower ratchet mechanism extending axially and circumferentially about the outwardly facing surface. The first lower ratchet mechanism is circumferentially spaced from the second lower ratchet mechanism. The second lower ratchet mechanism is configured to mesh with the second upper ratchet mechanisms at the one of the plurality of distinct ratcheting positions.

A method for adjusting a manhole cover includes moving an inner cylinder axially in a first direction from a first position, rotating the inner cylinder relative to an outer cylinder, and moving the inner cylinder axially in a direction opposite the first direction to a second position. The first position is axially distinct from the second position.

In another example of the foregoing method, the cover plate is integral with the inner cylinder.

In another example of the foregoing method, the first position provides a first elevation of the cover plate and the second position provides a second elevation of the cover plate. The first elevation is different from the second elevation.

In another example of the foregoing method, before the first direction moving step, inserting a tool into an opening in the cover plate.

In another example of the foregoing method, the inner cylinder includes a first ratchet mechanism, and the outer cylinder includes a second ratchet mechanism configured to mesh with the first ratchet mechanism at a plurality of distinct ratcheting positions.

In another example of the foregoing method, moving the inner cylinder axially in a first direction disengages an upper ratchet mechanism from a lower ratchet mechanism.

In another example of the foregoing method, moving the inner cylinder axially in a second direction reengages the upper ratchet mechanism with the lower ratchet mechanism.

In another example of the foregoing method, moving the inner cylinder axially in a first direction is an upward lifting movement.

The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

FIG. 1 shows a perspective view of an example adjustable manhole cover assembly at a first axial position.

FIG. 1A shows a ratchet mechanism of the adjustable manhole cover assembly of FIG. 1.

FIG. 1B shows a cross-sectional view of the adjustable manhole cover assembly of FIG. 1 within an access hole.

FIG. 2 shows a perspective view of an example outer cylinder of the adjustable manhole cover assembly of FIG. 1.

FIG. 3 shows a perspective view of an example inner cylinder of the adjustable manhole cover assembly of FIG. 1.

FIG. 4 shows a top view of an example cover of the adjustable manhole cover assembly of FIG. 1.

FIG. 5 illustrates an example tool for adjustment of the adjustable manhole cover assembly of FIG. 1.

FIG. 6 shows a perspective view of the adjustable manhole cover assembly of FIG. 1 at a different axial position.

FIG. 6A shows a ratchet mechanism of the adjustable manhole cover assembly of FIG. 6.

FIG. 6B shows a cross-sectional view of the adjustable manhole cover assembly at the axial position of FIG. 6 within an access hole.

FIG. 7 shows a cross-sectional view of the adjustable manhole cover assembly and an example retainer ring.

FIG. 8 illustrates an example smoothing tool.

FIG. 9A illustrates the example smoothing tool of FIG. 8.

FIG. 9B illustrates the example smoothing tool of FIGS. 8-9A.

FIG. 9C illustrates the example smoothing tool of FIGS. 8-9B.

FIG. 10 schematically illustrates the use of the smoothing tool of FIGS. 8-9C.

FIG. 11 schematically illustrates an example tool that may be used to lift and lower cylinders.

FIG. 12 illustrates an example lock, which may be used with the tool of FIG. 11.

FIG. 13 illustrates the lock of FIG. 12.

FIG. 14 illustrates the example tool engaged with an example outer cylinder.

FIG. 15 illustrates the example tool engaged with an example inner cylinder.

DETAILED DESCRIPTION

Referring to FIGS. 1 to 4, an example adjustable manhole cover assembly 10 includes an outer cylinder 12 and an inner cylinder 14. The outer cylinder 12 receives the inner cylinder 14 such that the outer cylinder 12 is radially outward of the inner cylinder 14 when disposed about an axis A. A cover plate 16 is disposed on the inner cylinder 14 in this example.

In this embodiment, the outer cylinder 12 is secured within an access hole 15 in a surface 19, one example being a road. The inner cylinder 14 is then lowered within the outer cylinder 12, effectively covering the access hole 15 with cover plate 16.

An access hole may be any opening in a floor, pavement, or other surface. In one example, an access hole provides human access to an underground utility vault, such as sewers, telephone, electricity, storm drains or gas.

Over time, the manhole cover assembly 10 may sink within the access hole 15 relative to the surrounding surface 19, causing the relative height of cover plate 16 to be lower than the surrounding surface 19, as shown in FIG. 1B.

The outer cylinder 12 includes an inner surface 17 having at least one ratchet mechanism 18. The example inner surface 17 includes four ratchet mechanisms 18 circumferentially spaced from one another and distributed about the axis A. More than four or fewer than four ratchet mechanisms 18 could be used in other examples.

Each example ratchet mechanism 18 is a linear gear with teeth 19. The ratchet mechanism 18 extends axially and circumferentially along the inner surface 17, extending circumferentially clockwise as it extends axially upward toward the cover plate 16. The teeth 19 provide a plurality of distinct ratcheting positions.

The outer cylinder 12 further includes an annular ring 20 extending radially outward from an outer surface 21 and at the uppermost edge of the outer cylinder 12. The outer cylinder 12 is configured to be secured to a manhole. In one example, the ring 20 provides a contact surface for features within the manhole, such that the features provide an upward force on the outer cylinder 12 to oppose the downward gravitational force on the outer cylinder 12.

The outer surface 26 of the inner cylinder 14 includes at least one ratchet mechanism 28. The example includes four ratchet mechanisms 28 spaced circumferentially from one another. More than four or fewer than four ratchet mechanisms 28 could be used in other examples. Each example ratchet mechanism 28 is a linear gear with teeth 29 and extends both axially and circumferentially along the outer surface 26, extending circumferentially clockwise as they extend axially upward toward the cover plate 16.

The ratchet mechanisms 28 are configured to mesh with the ratchet mechanisms 18 of the outer cylinder 12. Thus, the number of ratchet mechanisms 28 of the inner cylinder 14 is equal to the number of ratchet mechanisms 18 of the outer cylinder 12. The teeth 29 are configured to mesh with the teeth 19 of the corresponding ratchet mechanism 18, providing a plurality of distinct ratcheting positions for adjustment. The ratchet mechanisms 18, 28 may be cast with their respective cylinders or may be separate components attached to their respective cylinders.

Because the inner cylinder 14 is configured to be inserted through the top of the outer cylinder 12, the ratchet mechanisms 28 at a given circumferential position are axially above the ratchet mechanisms 18 at the given circumferential position when meshed. The ratchet mechanisms 18 are configured to support the inner cylinder 14 such that the inner cylinder 14 does not move downward relative to the outer cylinder when the ratchet mechanisms 18, 28 are engaged.

One of the outer cylinder 12 and the inner cylinder 14 can include a cover plate 16 for covering the manhole. The cover could be a separate structure in another example. In the example, the cover plate 16 is disposed on the inner cylinder 14. Further, the example cover plate 16 is integral with the inner cylinder 14, which can reduce the possibility of a cover plate blowout during a storm water surge.

The cover plate 16 includes a plurality of slots 22 configured to receive tools for adjusting the assembly 10. In the example, two slots 22 are utilized, but more or fewer slots are contemplated. The example slots 22 are spaced 180 degrees from each other, each at the same radial distance from axis “A”. The example slots 22 are linear and further illustrated in FIG. 4. Other types of openings are contemplated. The cover plate 16 extends radially outward of the outer surface 26 of the inner cylinder 14 to create an undersurface 24 of the cover plate 16. In one example, the annular ring 20 and the cover plate 16 extend a radially equal distance from the axis “A”.

FIG. 5 illustrates an example tool 30 for adjusting the assembly 10. The example tool 30 includes a handle 32 and a vertically linear member 33 extending from the handle 32. A horizontally linear member 34 is connected and perpendicular to the vertically linear member 33 at an opposite end from the handle 32.

The horizontal member 34 and the vertically linear member 33 are configured to be inserted into the slots 22. After insertion, the tool 30 is rotated 90° about an axis through the vertically linear member 33, whereupon the horizontally linear member 34 can be used to lift upward on a bottom surface of the cover plate 16, which in turn lifts the inner cylinder 14. This upward lifting will disengage ratchet mechanism 28 from ratchet mechanism 18, whereupon rotation of the cover plate 16 about the axis A in one direction will raise the cover plate 16 with respect to the outer cylinder 12, and rotation of the cover plate 16 about the axis A in the opposite direction will lower the cover plate 16 with respect to the outer cylinder 12. After rotation, the inner cylinder 14 may then be lowered to reengage the ratchet mechanism 18 with the ratchet mechanism 28. With an equal number of ratchet mechanisms 28 and 18, the assembly 10 self-aligns, not requiring any further alignment after adjustment.

A raised cover plate 16 and inner cylinder 14 are shown in FIG. 6. FIG. 6A shows the ratchet mechanism 18 engaged with the ratchet mechanism 28 when the cover plate 16 and inner cylinder 14 are at the position shown in FIG. 6. FIG. 1A shows the ratchet mechanism 18 engaged with the ratchet mechanism 28 when the cover plate 10 and inner cylinder 14 are at the position shown in FIG. 1, a lower axial position than the position shown in FIG. 6.

FIG. 6B shows the height of the cover plate 16 at the position shown in FIG. 6. The cover plate 16 can thus be adjusted to a vertical position relatively equal to the surrounding surface 19. In one example, the gap 40 between the radially outer edge of the cover plate 16 and the access hole 15 may then be filled.

FIG. 7 shows an alternative method for filling the gaps 40. A retainer ring 42 is provided around the outer circumference of the cover plate 16 before filler is added to the gap 40. The retainer ring 42 prevents filler from flowing downward to the gearing 18, 28. In one example, the thickness at the upper axial end of the retainer ring 42 is greater than the thickness at the lower axial end of the retainer ring 42, allowing for easy removal of the retainer ring 42 after the filler solidifies. The upper edge of the retainer ring 42 may be axially above the cover plate 16, also allowing for easy removal. The retainer ring 42 may be utilized for significant height differences between the cover plate 16 and the outer cylinder 12.

The example cover plate 16 has two slots 22, which would require two tools 30 for adjustment. This allows a single person to adjust the assembly 10, without assistance from machinery or other people. Further, because the example cover plate 16 is integral with the inner cylinder 14, the manhole remains covered during adjustment, substantially increasing safety.

The example assembly 10 has four ratchet gears offering full weight gearing, designed to be free of salt and sand and road debris contaminants.

FIG. 8 illustrates a smoothing tool 100 that may be used with a retainer ring, such as retainer ring 42 in some examples. The smoothing tool 100 includes a first portion 102 and a second portion 104 spaced apart by a gap 106. The first portion 102 and the second portion 104 are connected by a top portion 108. The gap 106 receives the retainer ring 42 when in use, with the first portion 102 radially outward of the retainer ring 42, and the second portion 104 radially inward of the retainer ring 42. The tool 100 may be moved about the circumference of the retainer ring 42 to smooth the filler that is radially outward of the retainer ring. The first portion 102 smooths the filler, while the second portion 104 provides for weight balance and handling of the tool 100.

FIGS. 9A-9C illustrate the example smoothing tool 100.

As shown in FIG. 9A the top portion 108 extends from the first portion 102, along the gap 106, to the second portion 104.

As shown in FIG. 9B, in some examples, the first portion 102 may include a tapered portion 110 provided by opposing sloped surfaces 112, 114. The first portion 102 may also include an extension portion 116 that meets the tapered portion 110 at a plane 118. In some examples, the plane 118 is configured to be axially aligned with the top of the retainer ring 42 (see FIG. 8) when the smoothing tool 100 is in use. The extension portion 116 may be non-tapered in some examples. The example tapered portion 110 tapers to a decreased thickness as it extends away from the plane 118, such that movement of the smoothing tool 100 about the circumference of the retainer ring 42 in either direction allows the filler to run along one of the sloped surfaces 112, 114 for smoothing. In other examples, the tapered portion 110 may include only one sloped surface.

As shown in FIG. 9C, the second portion 104 includes a substantially flat surface 120 for engagement of the cover plate 16 (See FIG. 1) during use of the smoothing tool 100. A tapered portion 122 is provided by opposing sloped surfaces 124, 126 adjacent the top portion 108. The tapered portion 122 tapers to a decreased thickness as it extends toward the top portion 108. The tapered portion 122 provides exposed undersurfaces 128, 130 of the top portion that can be engaged by a user's hand for ease of maneuvering the tool 100.

FIG. 10 schematically illustrates use of the smoothing tool 100. In the example shown, the sloped surface 112 smooths the filler (omitted for ease of viewing) when the tool 100 is moved in the direction C1 about the retainer ring 42. The sloped surface 114 smooths the filler when the tool 100 is moved in the direction C2 about the retainer ring.

FIG. 11 illustrates an example tool 200 that may be utilized to lift and lower cylinders, including each of the inner cylinder 14 and outer cylinder 12 (See FIG. 1) in some examples. The tool 200 includes a first arm 202 and a second arm 204 pivotally connected at a pivot point 206. A lock 208 (shown schematically) may be engaged to fix the first arm 202 relative to the second arm 204 and disengaged to allow the first arm 202 and second arm 204 to pivot relative to one another.

An extension 212 extends from an end 210 of the arm 202. An inner pin 214 extends in a first direction from the extension 212, and an outer pin 216 extends in a second, opposite direction from the extension 212. The inner pin 214 and outer pin 216 are one continuous member in some examples. The arm 202 and extension 212 form an angle 219 greater than 90 degrees in some examples. At an end 218 of the arm 202 opposite the end 210, a handle 220 may be received for handling the tool 200. In the illustrative example, the handle 220 is a chain, but other handles may be utilized.

An extension 224 extends from an end 222 of the arm 204. An inner pin 226 extends in a first direction from the extension 224, and an outer pin 228 extends in a second, opposite direction from the extension 224. At an end 230 of the arm 204 opposite the end 222, the handle 220 is received for handling the tool 200. The arms 202, 204 are substantially identical in some examples.

In the example shown, the lock 208 is situated between the pivot point 206 and the ends 218, 230. Other locations for the lock 208 are contemplated.

FIG. 12 illustrates an example lock 208, a plate 232 extends from the first arm 202 and is rotatably connected to a second plate 234 at a pivot point 236. The example plate 232 is fixed to the arm 202. Flanges 238, 240 extend outward from the plate 234 and receive a pin member 241. Pins 242, 244 extend from the pin member 241 substantially parallel to one another and substantially perpendicular to an axis of rotation of the pin member 241. In other examples, the pins 242, 244 are non-parallel. The pins 242, 244 are spaced apart such that the space between them may receive a portion 246 of the arm 204 when the lock 208 is in the locked position, which prevents rotation of the plate 234 relative to the plate 232.

FIG. 13 illustrates the lock 208 with the pins 242, 244 disengaged from the portion 246. The plate 234 is therefore free to rotate relative to the plate 232. In the example, the plate 234 rotates out of a slot 247 in the arm 204, and the arms 202, 204 are free to pivot relative to one another about the pivot point 206. The slot 247 secures the plate 234 when in the locked position.

FIG. 14 illustrates the tool 200 engaged with the outer cylinder 12. The outer pins 216, 228 (not shown; see FIG. 11) are received within openings 250 in the outer cylinder 12. The lock 208 is in a fixed position such that the arms 202, 204 cannot move relative to one another about the pivot point 206.

FIG. 15 illustrates the tool 200 engaged with the inner cylinder 14. The inner pins 214, 226 engage the inner cylinder 14. In some examples, the pins 214, 226 engage openings 252 in the inner cylinder 14 as shown; in other examples, the pins 214, 226 engage the undersurface of the cover plate 16. The lock 208 is in a disengaged position when the tool 200 engages the inner cylinder, such that the arms 202, 204 can pivot relative to one another. When the handle is utilized the ends 210, 222 of the arms 202, 204 are biased toward one another to engage the cylinder 14. The same tool 200 can therefore be utilized for both cylinders 12, 14.

The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims. 

What is claimed is:
 1. A method for adjusting a manhole cover comprising: inserting a first tool into a first opening in a cover plate of an inner cylinder; inserting a second tool into a second opening in the cover plate spaced from the first opening; rotating the first tool and the second tool after insertion into the openings; moving the inner cylinder axially in a first direction from a first position, wherein the moving includes lifting the first tool and the second tool to engage an undersurface of the cover plate and lifting the cover plate; rotating the inner cylinder relative to an outer cylinder; and moving the inner cylinder axially in a second direction opposite the first direction to a second position, wherein the first position is axially distinct from the second position.
 2. The method as recited in claim 1, wherein the first position provides a first elevation of the cover plate, the second position provides a second elevation of the cover plate, and the first elevation is different from the second elevation.
 3. The method as recited in claim 1, wherein the inner cylinder includes a first ratchet mechanism, and the outer cylinder includes a second ratchet mechanism configured to mesh with the first ratchet mechanism at a plurality of distinct ratcheting positions.
 4. The method as recited in claim 3, wherein the moving the inner cylinder axially in a first direction disengages the first ratchet mechanism from the second ratchet mechanism.
 5. The method as recited in claim 4, wherein the moving the inner cylinder axially in a second direction reengages the first ratchet mechanism with the second ratchet mechanism.
 6. The method as recited in claim 1, comprising: placing a retainer ring around an outer circumference of the cover plate; providing filler around an outer surface of the retainer ring, such that the retainer ring is disposed between the cover plate and the filler; and removing the retainer ring.
 7. The method as recited in claim 6, wherein the retainer ring is tapered such that a thickness at an upper axial end of the retainer ring is greater than a thickness at a lower axial end of the retainer ring for ease of removal.
 8. The method as recited in claim 6, comprising: before the filler solidifies, smoothing out the filler with a smoothing tool including a first portion and a second portion spaced apart by a gap, the first portion includes a tapered portion, wherein the smoothing includes positioning the smoothing tool such that the retainer ring is received in the gap, and moving the smoothing tool about a circumference of the retainer ring to engage the tapered portion with the filler.
 9. The method as recited in claim 3, wherein the moving disengages the first ratchet mechanism from the second ratchet mechanism, and the opening is a linear slot, wherein each of the first tool and the second tool includes a handle, a vertical member extending from the handle, and a horizontal member transverse to the vertical member, such that the inserting step includes inserting the vertical member and the horizontal member into the linear slot, the rotating the first tool and the second tool step includes rotating the vertical member and the horizontal member, and the lifting step includes engaging the horizontal member with the undersurface of the cover plate to provide a lifting force on the inner cylinder to disengage the first ratchet mechanism from the second ratchet mechanism.
 10. A method for adjusting a manhole cover comprising: inserting a first tool into a first opening in a cover plate of a first cylinder; inserting a second tool into a second opening in the cover plate spaced from the first opening; rotating the first tool and the second tool after insertion into the openings; moving the first cylinder axially in a first direction from a first position, wherein the moving includes lifting the first tool and the second tool to engage an undersurface of the cover plate and lifting the cover plate; rotating the first cylinder relative to a second cylinder; and moving the first cylinder axially in a second direction opposite the first direction to a second position, wherein the first position is axially distinct from the second position.
 11. The method as recited in claim 10, wherein each of the first tool and the second tool includes a handle, a vertical member extending from the handle, and a horizontal member transverse to the vertical member, such that the inserting step includes inserting the vertical member and the horizontal member into the opening, the rotating the first tool and the second tool step includes rotating the vertical member and the horizontal member, and the lifting step includes engaging the horizontal member with the undersurface of the cover plate to provide a lifting force on the first cylinder.
 12. The method as recited in claim 11, comprising placing a retainer ring around an outer circumference of the cover plate; providing filler around an outer surface of the retainer ring, such that the retainer ring is disposed between the cover plate and the filler; and removing the retainer ring.
 13. The method as recited in claim 12, wherein the retainer ring is tapered such that a thickness at an upper axial end of the retainer ring is greater than a thickness at a lower axial end of the retainer ring for ease of removal.
 14. The method as recited in claim 13, wherein the first cylinder includes a first ratchet mechanism, and the second cylinder includes a second ratchet mechanism configured to mesh with the first ratchet mechanism at a plurality of distinct ratcheting positions.
 15. The method as recited in claim 14, wherein the first cylinder is an inner cylinder, and the second cylinder is an outer cylinder.
 16. The method as recited in claim 14, wherein the first ratchet mechanism is a linear gear with teeth.
 17. The method as recited in claim 10, wherein the cover plate in the second position is elevated relative to the cover plate in the first position.
 18. A method for adjusting a manhole cover comprising: inserting a first tool into a first linear slot in a cover plate integral with an inner cylinder; inserting a second tool into a second linear slot in the cover plate spaced from the first linear slot, wherein each of the first tool and the second tool includes a handle, a vertical member extending from the handle, and a horizontal member transverse to the vertical member, such that the inserting step includes inserting the vertical member and the horizontal member into the linear slot; rotating the first tool and the second tool after insertion into the openings, including rotating the vertical member and the horizontal member; moving the inner cylinder axially in a first direction from a first position, wherein the moving includes lifting the first tool and the second tool to engage the horizontal member with the undersurface of the cover plate to provide a lifting force on the inner cylinder to disengage a first ratchet mechanism from a second ratchet mechanism and lift the inner cylinder and cover plate, wherein the inner cylinder includes the first ratchet mechanism and the outer cylinder includes the second ratchet mechanism; rotating the inner cylinder relative to an outer cylinder; and moving the inner cylinder axially in a second direction opposite the first direction to a second position, wherein the first position is axially distinct from the second position.
 19. The method as recited in claim 18, comprising: placing a retainer ring around an outer circumference of the cover plate; providing filler around an outer surface of the retainer ring, such that the retainer ring is disposed between the cover plate and the filler; and removing the retainer ring, wherein the retainer ring is tapered such that a thickness at an upper axial end of the retainer ring is greater than a thickness at a lower axial end of the retainer ring for ease of removal.
 20. The method as recited in claim 18, wherein the first ratchet mechanism is a linear gear with teeth. 